Measuring device for precision grinders



1931. F. H. WHITMAN MEASURING DEVICE FOR PRECISION GRINDERS Filed March12, 192 8 INVENTOR. FRED H. WHITMAN ATTORNEY.

Patented Dec. 1, 1931 NITED STATES PATENT OFFICE FRED H. WHITMAN, OIMILWAUKEE, WISCONSIN, ABSIGNOR TO A. 0. SMITH (DRPORA- TION, OIMILWAUKEE, WISCONSIN, A CORPORATION OF NEW YORK IEASUBING DEVICE FORPRECISION GBINDERS Application filed larch 12, 1928. Serial No. 260,874.

The invention relates to a measuring device adapted for use inconnection with apparatus for accomplishing precision grinding.

The purpose of my invention is to produce a device for the automaticgaging to close limits of finished metal arts which will be providedwith means wiereby cessation of the grinding operation upon a metal partcan be effected immediately when said part has obtained a predetermineddegree of precision.

The novel device consists of a primary mechanism including a gagingelement adapted to directly contact'with the face of a metal part beingground and means set up to function in conjunction with said gagingelement to cause cessation of the grinding operation when the metal parthas the desired gage, and a secondar or measuring mechanism also set upto auction in conpmction with the gaging element, to indicate the gageof said metal part.

Having brieil stated the general nature of the invention, shall nowparticularly describe the features thereof, and later specifically pointout the novelty of said features in the claims hereto appended.

Fig. 1 is a side elevational view of a measuring device made inaccordance with the invention and as applied to use, disclosing, indotted lines, so much of a; precision grinding machine as is necessaryto illustrate the prineiples of the invention.

Fig. 2 is a sectional View of the measuring device, on line 2-2 in Fig.1.

Fig. 3 is a sectional view on line 33 in Fi 1, detailing the shoecam'for the cam rol er.

With respect to the drawings, 10 and 11 indicate the stationary andreciprocable mem' hers, respectively, of a precision grinder, 12designates a piece of work fixed upon said reciprocable member to beoperated upon by a grinding element (not shown), and 13 represents,generally, the measuring device of the present invention.

Of said measuring device, 1; is a main bracket secured, as at 15, uponthe stationary member 10 of the grinder, and suitably supporting asmaller bracket 16 adjacent t e work 12 and a column 17 at fartherdistance from said work. The smaller bracket 16 supports a gaging lever18 and a cam roller lever 19.

As disclosed, the gaging lever 18 is pivotally attached, as at 20, tothe upper portion of the smaller bracket 16 between spaced ears thereof,and is constituted by two arms, designated 21 and 22, the formerextending vertically u ward from the pivot 20, and the latter exten inghorizontally from said pivot in direction toward the column 17.

An integral sleeve 23 upon the arm 21 of the gaging lever houses a 0st-24 adapted to be longitudinally adjusted in said sleeve, as by a screw25, and locked in adjusted position therein, as by a clamp screw 26. Asteel gaging pin 27 carried by said post has a preferably slightlyspherical head adapted to directly contact with the face of the workbeing ground. See Fig. 1.

The arm 22 of the gagin lever is desirably several times as long as thearm 21 thereof. At its extremity spaced from the pivot 20, said arm 22is provided with an upstanding properly insulated contactor 28, and adjacent said extremit said arm has an H standing steel pin 29 the head ofwhich is preferably slightly spherical.

The contactor 28 is in a relay (not shown), for actuating a stop motion,or other suitable mechanism for discontinuing the grinding operationupon a metal part, as will be un-- derstood, and said contactor 28 isadapted to engage a mating properly insulated contactor 30, suitablycarried by a clamp arm 31 on the column 17 and also in the relay.

A gage or other suitable measuring device 32 supported upon the column17 in any convenient manner (not shown), has its gaging pin 33 situatedto be engaged by the steel pin 29.

The cam roller lever 19 is situated directlybelow the gaging lever 18,between the ears of the bracket 16, and is arranged parallel with thearm 22 thereof. One end of said cam. roller lever is pivoted, as at 34,upon the ears of said smaller bracket, and the other end thereof carriesa steel roller 35 adapted to engage a shoe cam 36 located upon the re- Iciprocable member 11 of the grinder in any convenient way.

A sensitive compression spring'37 interposed between the lower face ofthe arm 22 of the aging'lever and the upper face of the cam ro ler leverprovides means for resiliently supporting the gaging lever upon said camroller lever.

An upstanding stop 38 upon .the smaller bracket 16, between its ears,and beneath the cam roller lever is adapted to limit the extent ofdownward movement of said cam roller lever.

The shoe cam 36 is situated at one end por tion of the reciprocablemember 11, so that during the major portion of the stroke of saidmember, the cam roller lever 19 is resting upon the stop 38. At suchtime, both the cam roller 35 and the gaging pin 27 are unengaged. \Vhen,however, the shoe cam'36 reaches the location of the cam roller 35 theoblique surface 39 of said shoe cam rides under the roller 35 andelevates the roller lever and swings the arm 22 of the gaging leverupward to an extent bringing the ga ing pin 27 into engagement with theface of the work being ground.

Upon the movement of the shoe cam in reverse direction, the camroller'rides off of said shoe cam and the cam roller lever falls to thestop 38. The arm 22 of the gaging lever is constructed to overbalancethe arm 21 and its sleeve, so that said arm 22 follows the cam rollerlever in its downward movement and thus removes the gaging .pin

' from the work.

The-end portion ofthe arm 22 of the gaging lever which contains thecontactor 28 and the steel pin 29 can move upwardly only to the extentpermitted by the condition of the face of the work being ground. Theengagement of said steel pin 29 with the gaging pin 33 affords anarrangement for indicating the gage of said face of the work from timeto time, as will be obvious. The contactor 30 is set at elevationrelatively to the gaging lever and its arm 22 to permit engagement ofthe contactor 28 with said contactor 30 upon the engagement of thegaging pin 27 with a face of the work which has become ground to adegree of precision already predetermined. Immediately upon engagementof the contactors with each other, the relay having said contactors isbrought into play to actuate any suitable type of mechanism, as, forexample, a stop motion device, adapted to terminate the grindingoperation.

Manual meansincluding a sensitive com pression spring 40 resting againsta finger lever 41 accessibly situated upon the sleeve 23 can be utilizedto manually measure the gage of the work without interruption of themechanical gaging.

The lever 41 may be operated to bring the gage element into contact withthe workpiece irrespective of the cam operating mechanism so t at thepiece may be gaged at any desired time.

Having thus described the invention, what I claim and desire to secureby Letters Patent of the United States, is:

1. A measuring device for precision grinders comprising a gagingelement, means for periodically causing said gaging element to contactwith the piece being Worked, measuring mechanism functioning inconjunction with said gaging element for indicating the gage of saidworkpiece, and additional means functioning in conjunction with saidgaging element and adapted to cause the termination of the workingoperation when the piece being worked has attained a predetermineddegree of precision.

2. A measuring device for precision grinders comprising a support, abell crank pivoted to said support, a gaging element associated with'onearm of said bell crank, indicating means associated with the other armof said bell crank and functioning in conjunction with said gagingelement, and means for periodically causing said gaging element tocontact with the piece being worked to indicate the gage of said workpiece.

3. measuring device for precision grinders comprising a support, a bellcrank pivotally mounted on said support, a gaging element adjustablyconnected to one arm of said bell crank, indicatin means associated withthe other arm of sai bell crank and op erating in conjunction with saidgaging element, means for normally maintaining said gaging element outof contact with the Workpiece, means for periodically causing saidgaging element to contact with the workpiece to indicate the gage ofsaid work, and means adapted to cause the cessation of the workingoperation when the workpiece has attained a predetermined degree ofprecision.

4. A measuring device for precision grinders comprising a sup ort, abell crank pivotally mounted on said support, a gaging element connectedto one arm of said bell crank, indicating means associated with theother arm of said bell crank, means for normally maintaining said gagingelement out of contact with the iece being worked, and cam means forperiodically causing said gaging element to contact with the work and toindicate the gage thereof.

5. A measuring device for precision grinders comprising a support, abell crank pivotally connected to said support, a gaging elementconnected to one arm of said bell crank,

indicating means associated with the other arm of said bell crank andoperating in conjunction with said gaging element, a lever latingportion of the grinder, said cam causing a pivotal movement of said bellcrank at periodic intervals to cause the gaging element to contact withthe piece being worked and to indicate the ga e thereof.

6. A measuring evice for precision grinders comprising a support, a bellcrank mounted on said support, a ga 'ng element connected to one arm ofsaid he] crank, indicatin means associated with the other arm of saidbell crank and operating in conjunction with said gaging element, andmeans for periodically imparting a pivotal movement of said bell crankto cause said aging element to contact with said workpiece to therebyindicate the gage thereof. 7

7. A measuring device for precision grinders, comprising a gagingelement including a movable electrical contactor and means for actuatinga measuring unit, a fixed electrical contactor normally in spacedrelation to said movable contactor, a measuring unit adjacent saidmeans, and mechanism resiliently urging said gagm element intoengagement with the face'o a metal part being ground, the movablecontactor thereof in direction toward the fixed contactor, and the meansinto operative engagement with the measurin unit to indicate the gage ofsaid face as t e grindin operation rogresses, said fixed contactor beingsituated to be engaged by said movable contactor when said enga ed faceof the metal part being ground has 0 tained a predetermined degree ofprecision.

8. In a measuring device for, precision grinders, a pivoted gagingelement having an overbalancing arm, a pivoted lever below said arm, acompression sprin for supporting said arm upon said lever, said leverbeing normally positioned to cause said overbalancin arm to positionsaid gaging element in s ace relation to the face of a metal part ingground, and a shoe cam adapted to ride unifngly urge said gaging elementagainst said ace.

9. A measuring device for precision grinders comprising a gagingelement, a movable electrical contactor operated by said gagin element,a measuring unit, means operate by said gaging element for operatingsaid measurin tactor normall y in spaced relation to said movablecontactor and means operable at periodic intervals for resilientlyurging said gaging element into contact with the metal part beingground, the movable contactor in the direction of the fixed contactorand the measuring unit actuating means into operative engagement withthe measuring unit.

10. A measuring device for precision grinders comprising a gagingelement, an oscillating carriage adapted to su port the work to beground, means operab e on each r said lever and elevate the same toyield- 1 oscillation of the carria to cause the gaging element totemporarily contact with t e work, and means functioning in conjunctionwith said gaging element adapted to cause a termination of the workinoperation when the work piece has attaine a predetermined de ree ofprecision.

te'stimon whereof, I have signed my name at Mi waukee, this 28th day ofFebruary, 1928.

FRED H. WHITMAN.

unit, a fixed electrlcal con- 1

